Method and apparatus for forming fibers



Aug. 5, 1952 E..R. POWELL METHOD AND APPARATUS FOR FORMING IBER-S BY/U 0Filed Sept. 50. 1949 IT' ENT R ATTORNEY Patented Aug. 5, 1952 liiETHODAND APPARATUS FOR FORMING FIBERS Edward R. Powell, North Plainfield, N.J., as-

signor to Johns-Manville Corporation, New York, N. Y., a corporation ofNew York Application September 30, 1949, Serial No. 118,815

18 Claims.

The instant invention relates to a method and apparatus for producinfine fibers and, although it is particularly directed to, and will bedescribed in connection with the manufacture of fibers from glass andsimilar thermoplastic or meltable materials, it is not to be consideredas limited to such materials. Other plastic materials, such aspolystyrene and melamine resins, and the like, from which fibers may bedrawn can also be employed. The term glass is used herein in a genericsense to include glass compositions, synthetic low alkali glass, naturalglass, mineral wool compositions, and the like.

A principal object of the invention is the provision of an economicalmethod and apparatus for the production of extremely fine and shot-freefibers.

The methods previously proposed for the production of fine glass fibershave, for the most part, required the formation of relatively fine glassrods and their reduction to a multiplicity of fibers by feeding theminto a high speed, high temperature, gaseous blast by which they areremelted and drawn or blown into fibrous form. An object of the instantinvention is th provision of a method and apparatus which, in contrastto th prior methods referred to above, employs the operations of drawingpreferably a plurality of filaments from a relatively viscous body ofglass and further attenuating the individual filaments into finefilaments or fibers Without reheating. The method permits the use ofmore viscous melts than the prior methods and produces longer, moreshot-free fibers.

A further object of the invention is the provision of a fiber formingapparatus which is economical in performance and operation and which iscompactly arranged to require a minimum of space.

Briefly stated, the invention resides in a process comprising the stepsof forming a layer of molten glass, moving a series of pins orprojections into contact with and then away from the layer to drawfilaments from the layer, and attenuating such filaments into long finefibers by applying a drawing force transversely to the lengths of thefilaments and while they are, at least during the major portion of thdrawing operation, still attached to atleast one of the elements. Theinvention also resides in the apparatus for carrying out such method.

My invention will be mor fully understood and further objects andadvantages will become apparent when reference is made to the mordetailed description of a preferred embodiment of 2 the invention whichis to follow and to the accompanying drawings in which:

Fig. 1 is a View, partially in section and partially in elevation,illustrating an apparatus embodying the instant invention;

Fig. 2 is a sectional view taken on the line 2--2 of Fig. 1;

Fig. 3 is a sectional view, on an enlarged scale, taken on the line 3-3of Fig. 2;

Fig. 4 is a sectional view, on an enlargedscal taken on the line 4-4 ofFig. 1; and,

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2.

Referring now to the drawings, the apparatus includes a rotor Illmounted on a shaft l2 for rotation in the direction indicated by arrowl3. Rotor I0 is of a construction to resist Warpage and excessivedeterioration and wearunder the temperatures involved which forconventional glasses may run as high, for example, as 1900 F. to 2100 F.Suitably for this purpos it includes-a tire It made of a heat-resistantmetal, such as non-ferrous nichrome, connected to a hub [6 by spokes [8,the intervals between the spokes being filled with a high temperatureinsulating mate-'- rial 20. The tire can also be of a suitable ceramicmaterial. A second rotor 22 is mounted on a shaft 24 lying inparallelism with shaft I2. Rotorsv I0 and 22 are in alignment andportions of their peripheral surfaces lie in adjacent parallel, butnoncontacting relationship, as will be later more fully explained. Theperipheralsurface of rotor I0 is smooth whil that of rotor 22 isprovided with a multiplicity of protuberances, specifically pins orprojections 26, suitably equally spaced at relatively close intervalsover the peripheral surface of the rotor. For example, the protuberancesmay be placed from 64. to 400 per sq. in. Rotor 22, except for theprotuberances, is of similar construction to rotor l0 and is mounted forrotation in the direction indicated by arrow 27; that is, in a directionopposite to rotor ID. The rotors are driven by any suitabl means subjectto speed control, the drive being diagrammaticallyillustrated at 28. l

A glass melting furnace 29 of any conventional or suitable type ismounted above the rotors with an outlet orifice 30. positioned todischarge a stream of glass 32 onto rotor mat a point on: a downturningarc of its peripheral surface.

A rockable shaft 34, mounted in suitable bearings, 36, carries a wiperblade 38 fixed to the shaft for movementwith the shaft, whereby theWiping edge of the blade'may be adjusted toward and away from thesurface of rotor ID to spread the a movement of the stretching disc.

material of stream 32 to a layer of predetermined thickness on thesurface of the rotor. Suitable means may be employed for rocking shaft 33 to provide the desired adjustment within close tolerances. Such meansis diagrammatically illustrated as a micrometer adjustment it.

A stretching disc 42 is mounted for rotation in the direction indicatedby the arrow on a shaft 44, the disc being positioned to have adownturning are of its peripheral surface intercept fibers formedbetween the rotors. Opposite the stretching disc is a pusher wheel 45,mounted on a shaft 48 for rotation in a direction opposite to that ofthe stretching disc, as indicated by the arrow and at preferably thesame peripheral speed. The periphery of the pushing wheel intercepts thefibers which are beyond the path of The shafts of the stretching discand pusher wheel may be driven by any suitable mechanism indicateddiagrammatically at 50. The periphery of disc d2 carries a continuousseries of forwardly slanting pins 52 adapted to hook the fibers andcarry them downwardly upon rotation of the disc. Pusher wheel 46 issuitably centrally grooved (see Fig. 3) and mounted relatively to thedisc to receive the tips of the pins in the groove. The peripheralflanges defining the groove are preferably notched, as indicated, toprevent slipping of the fibers.

Means are provided for stripping fibers from the, stretching disc andfor further drawing the fibers. Such means comprise gaseous jetsdirected downwardly adjacent the periphery of the disc and substantiallyat the point where the pins 52 point approximately downwardly. Suitablythe jets are issued from a V-shaped nozzle 54 (see particularly Fig.having a series of orifices 56 pointing inwardly and downwardly todirect the jets in converging paths. The nozzle is connected by a line.58 to a supply of any suitable gas under pressure, such as compressedair or superheated steam. As will be appreciated, in lieu of asingleV-shaped nozzle, separate nozzles on opposite sides of the stretchingdisc may be used. Also, a nozzle located only on one side of the disc isoperable but does not have the efficiency of other types which deliverconverging jets.

The apparatus described above, with the exception of furnace 29, thatis, rotors It and 22, the working portions of thestretching disc and thepusher wheel, and nozzle 54, are substantially enclosed by a casing 59.The casing is cut away at the bottom to points approximately beneath therotor shafts, the cut away portions extending up the side wallssufficiently to provide clearance for the stretching disc, pusher wheel,nozzle, etc. An opening 60 is also provided in the upper Walls of thecasingfor the entry of stream 32. The casing may consist of a steelshell 62 lined with a refractory material 64 of a character to resistthe temperatures involved. The casing is .of a Width to closely embracethe rotors, as illustrated particularly in Fig. 2, and is of such lengthand height that the refractory lining is relatively close to the rotorperipheries. Burners 66 are mountedin apertures in the upper corners atthe opposite ends of the casing. Each of the burners is positioned todirect its flame along the refractory walls of the casing. The flamesextend completely along the walls, and tongues of flame issue frombetween the rotors and lower walls of the casing. The rotors andthe'airspaces between thewalls and the rotors are thus principallyheated byradiation-from the refractory d walls. The burners, which may be ofconven tional type, are connected by lines 6'! to a supply (not shown)of a fuel such as a mixture of gas and air.

Suitable means are provided below the casing for collection of thefibers produced by the apparatus described above. This may comprise aforaminous or openwork conveyor 68 on which the fibers settle from anaeriform suspension to be continuously carried from the place offormation. A suction box (not shown) may be located below the upperreach of the conveyor to aid in the fiber collecting and feltingoperation.

In the operation of the apparatus and in carrying out the method of theinstant invention for the formation of glass fibers, a suitable glasscomposition, which may be any of those available for fiber drawing, ismelted in furnace 29 and is discharged as a continuous stream or asuccession of drops or wads, both being referred to as stream 32,through orifice 30, the stream falling onto a downturning arc of theperipheral surface of rotor It. The body of material collected on therotor is carried beneath blade 38 where it is spread width-wise of therotor surface and leveled off to a layer of predetermined thickness bythe blade. The blade is adjusted to leave a layer of such thickness thatprojections 36 on rotor 22 dip into the layer, but the layer is notsqueezed or placed under pressure between the rotors. Rotors it and 22are driven at the same, or substantially the same speed, and in oppositedirections, as previously mentioned.

Burners 65 direct their flames along the walls of the casing, asexplained above, and are adjusted to such intensity that the spacesinside the casing and the surfaces of the rotors, including pins 26, aremaintained at temperatures sufficiently above the melting point of theparticular glass used that the glass carried by the rotors is in amolten but viscous state.

As the surfaces of the rotors move apart, each of the projections 25which contacts or dips into the layer of glass draws a fiber whereby amultiplicity of parallel fibers extend from the ends of the projectionsto the layer, the fibers being stretched, elongated, and further drawnas the surfaces of the rotors separate. Due to the fact that the pinsare maintained at temperatures above the melting point of the glass, asmentioned above, the projections do not tend to accumulate glass onsuccessive rotation of the rotors, an equilibrium point being quicklyreached at which the amount of glass on the projections is substantiallyconstant. The parallel fibers are carried into a position where they arepicked up by the pins 52 of the stretching disc or are pushed by thepusher wheel into positions where they will be picked up by the pins.The stretching disc draws the fibers into extended Vs with the ends ofthe fibers still connected t the projections and to the glass layer.

The stretching disc carries the Vs into the convergence of the gaseousjets issuing from nozzle 5d, the blast of the jets impinging on thefilaments and sliding them off the pins of the stretching disc andelongating them by drawing additional glass from the rotors. of thefilaments to the pins 26 and to the layer of glass, or at least to oneof them, continues until the connected end or ends of the fibers reachthe points where they are impinged by the flame tips issuing frombetween the rotors and the bottom Walls of the casing. Particularlysince the fibers are still under the tensionof the blast, they areimmediately burned off. The fibers thus The connection aeoasoo formedare carried downwardly in the blast as velocity of, the steam blast may,of course, be

varied in relatively wide limits, depending on the glass melt and thecharacter of the fibers to be obtained; In operation it has, been foundthat the rotors may be driven from 500 to 800 feet per minute forsuccessful fiber drawing with conventional glasses. The blast issuingfrom nozzle 54 is maintained at a relatively high velocity, say, between6,000 and 20,000 feet per minutein order to draw long fine fibers.Either high temperature steam or compressed air may be employed for theblast as itexerts only a pulling, and not a melting function. Thestretching disc 42 is preferably driven at surface speed substantiallytwice or three times that of the rotors. say speeds of the order of1,000 to 1,500 feet per minute. The apparatus is compact and highlyefficient. A plurality of the devices may be placed side by side andsupplied with streams of glass from a line of orifices 30 in the glassmelting furnace 28. The heating system illustrated is highly efficientas the rotors are heated by directimpingement of the burner flames tosome extent but mostly by the heat radiated from the refractory walls ofthe casing. The flame tips issuing from between the rotors and lowerwall of the casing also cut off the fibers;, as explained above, andinsure that they will not be drawn into the casing.

Fiber diameter may be controlled by adjustment of the rate of. flow ofglass in relation to the rest of the equipment,- orby relativeadjuststyrene and melamine resins, may be reduced to fiber by theinstant method and apparatus. 7

Having thus described my invention in rather full detail, it will beunderstood that these details need not be strictly adhered to and thatvarious changes and modifications may suggest themselves to one skilledin the art, all falling Much longer fibers are:

within the scope of the invention as defined by 1 the subjoined claims.

What I claim is:

1. A method of making fibers from molten material comprising forming abody of the molten material, contacting said body at a plurality ofpoints by drawing means and drawing fibers from said body at said pointby moving said drawing means relatively to said body,-intercepting saidfibers during the fiber drawing operation by means moving in a directiontransverse to the fibers to elongate the same, and subjecting saidelongated fibers to the action of a gaseous blast to further elongatethem.

2. A method of making fibers from fiber forming material comprisingforming a layer of the material on a moving surface, contacting thelayer with a plurality of elements, moving the elements in a pathdiverging from that of the surface to draw fibers from said layer,grasping said fibers during thefiber drawing operation by means movingin a path transverse to the length of said fibers and carrying-themintothe path of a gaseous blast.

3. A method ofunaking fibers from molten terial comprising forming alayer of the molten material on the peripheral surface of a rotor,

contacting said layer by a succession of pins the fibers to the actionof the blast to elongate them.

4; In an apparatus for producing fibers, means for forming a body offiber forming material,

means movable relatively away from said body for contacting said bodyata plurality of points and drawing fibers therefrom, means for graspingsaid fibers at a point intermediate the ends thereof and stretching theminto Vs, and means for setting up afluid blast directed to elongate thefibers. 5. In an apparatus for producing fibers, amovtoward said Vs ablemember, means for forming a layer of fiber forming material on thesurfaceof the member, a second member carrying a plurality of elementsand mounted for movement of said elements into contact with said layerand then away from said layer whereby fibers are drawn by the elementsfrom the layenmeans for grasping said fibers intermediate the lengththereof and stretching them into Vs, and means for setting up a fluidblast moving toward said Vs.

6. In an apparatus for producing fibers, a'rotor having a peripheralsurface, means for forming a layer of fiber forming material thereon,asec- 0nd rotor having a plurality of elements projecting from theperipheral surface thereof, means for imounting said second rotor forcontact of said elements with the layer on said first rotor whereby,upon rotation of said rotors, fibers are drawn from said layer by saidelements, means including a plurality of elements moving in a directiontransverse to the lengthof said fibers to contact said fibers andstretch the same into Vs, and means for projecting a gaseous blastagainst said Vs to elongate the fibers. I

7. In an apparatus for producing fibers, a rotor having a peripheralsurface, means for forming a layer of fiber forming material thereon,means for controlling the thickness of said layer, a sec,- ond rotormounted adjacent said first rotor and having a plurality of elementsprojecting from the peripheral surface thereof for contacting the layeron said first rotor whereby, upon rotation of said rotors, fibers aredrawn from said layer, and means for applying forces to said fibersduring the drawing operation and in a direction transverse to the lengththereof to elongate said fibers.

8. In an apparatus for producing fibers, a rotor having a peripheralsurface, means for forming a layer of molten material on said surface, asec- 0nd rotor, fiber drawing means projecting from 9. In an apparatusfor producing fibers, a rotor havinga peripheral surface, means forformin a layer of molten material on said surface, a second rotor, fiberdrawing means projecting from the periphery of the second rotor, meansmounting said second rotor for rotation with said fiber drawing meansmoving into and out of contact with said layer to draw fibers therefrom,means projecting between said rotors for applying elongating forces tosaid fibers in directions transverse to the lengths thereof, meanspartially enclosing said rotors to leave an opening adjacent the bottomsof the rotors, and burners directed to set up flames extending along thewalls of said enclosure and into said opening whereby said walls radiateheat toward said molten layer and said flames burn ofi the ends of thefibers from the rotors. v

10. In an apparatus for producing fibers, a rotor having a peripheralsurface, means for forming a layer of molten material on said surface, asecond rotor, elements projecting from the periphery of the secondrotor, means mounting said second rotor for rotation with said elementsmoving into and out of contact with said layer to draw fibers therefrom,a stretching disc having a succession of extending elements, meansmounting said disc for rotation with said extending'elements moving in apath transverse to the directions of said fibers and to intercept fiberswhereby the intercepted fibers are hooked by said extending elements andstretched into Vs,.and means for removing said fibers from saidextending elements and further elongating the fibers.

11. In an apparatus for producing fibers, means for forming a continuoussuccession of fibers, a stretching disc having a succession of extendingelements, means mounting said disc for rotation with said extendingelements moving in a path transverse to the directions of said fibersand to intercept fibers, whereby the intercepted fibers are booked bysaid extending elements and stretched into Vs, and means for removingsaid fibers from said extending elements and further elongating thefibers.

12. In an apparatus for producing fibers, means for forming a continuoussuccession of fibers, a stretching disc having a succession of extendingelements moving in a path transverse to the directions of said fibersand to intercept fibers, a pusher wheel mounted for rotation oppositesaid disc to push fibers into position for interception by saidelements,whereby the fibers are hooked by said extending elements and drawn intoVs and means for removing said fibers from said exfrom saidbody to drawfibers therefrom, applying a force to each fiber in a directiongenerally transversely of the length thereof, and elongating said fibersby continued application of said forces while the respective ends ofsaid fibers are connected to said elements and said body.

15. A method of making fibersfrom fiber forming material comprisingforming a layer of the material on a moving surface, contacting thelayer with aplurality of elements, moving the elements in a pathdiverging from that of the surface to draw fibers from said layer,applying a force to each fiber in a direction generally transversely ofthe length thereof, and elongating said fibers by continued applicationof said forces while the respectiveends of said fibers are connected tosaid elements and said body.

16. Aimethod of making fibers from molten material comprising forming alayer of the molten material on the peripheral surface of a rotor,contacting said layer by a succession of projections extending from theperiphery of a second rotor, maintaining said projections attemperatures above the melting point of the material, rotating saidrotors in opposite directions whereby said projections draw fibers fromsaid layer, applying a force to each fiber in a direction generallytransversely of the. length thereof, and elongating said fibers bycontinued application of said forces while the respective ends of saidfibers are connected to said elements and said body.

17. An apparatus for producing fibers comprising, means for forming abody offiber forming material, a plurality of elements, means for movingsaid elements into contact with and then relatively away from said bodyto. drawfibers therefrom, a plurality of members relatively movable intocontact with intermediate portions of said fibers, and means for movingsaid members While in contact with said fibers in directions generallytransversely of the fiber lengths to elongate said fibers."

18. An apparatus .for producing fibers comprising a first rotor having aperipheral surface, means for forming a layer of fiber forming materialon said surface, a second rotor positioned adjacent said first rotor,projection means on said second rotor arranged to contact 'said layer,means for rotating said rotors whereby said projection means contact andthen move relatively tending elements and further elongating the 13. Amethod of making fibers comprising forming a body of fiber formingmaterial, contacting said body at a plurality of points, drawing fibersfrom the body at said points, applying a force to each fiberin adirection generally transversely of the length thereof, and elongatingsaid fibers by continued application of away from said layer;to drawfibers therefrom, a plurality of members relatively movable into contactwith intermediate portions of said fibers, and means for moving saidmembers while in contact with said fibers in directions generallytransversely of the fiber length to elongate said fibers.

EDWARD R. POWELL.

REFERENCES mm) The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,126,411 Powell a Aug. 9, 19382,385,358 Hanson Sept. 25, 1945 2,450,914 Powell Oct. 12, 1948 2,522,526Manning Sept. 19, 1950

